Improving the Wear Resistance of Barite Mining Tools

Abstract

Wearing of mining tools leads to high replacement costs, machine downtime and loss of business opportunities. This work was however, aimed at improving the wear resistance of AISI 1065 and 1070 proeutectoid steels used for (barite) mining operations. To achieve this, the case hardening method adopted was pack-cyaniding with dried and pulverized cassava leaves (a type of carbonitiriding) at 700, 800, 850 and 900°C. After the carbonitriding process, the 1065 steel was quenched and tempered at 300°C for 3hrs, whereas the 1070 was air cooled. As a result, the tempered martensitic 1065 steel formed, showed an increase in hardness of 706 HV over that of 540 HV obtained previously in literature with the same method. Pin-on- disk wear experiments were conducted on the as-received and carbonitrided pin samples. The result showed that at 900°C, the lowest wear rate, lowest coefficient of friction, highest hardness and highest strength were observed for the 1065 carbonitrided steel. Charpy impact results indicated that the toughness of the carbonitrided samples decreased, and reasons for this decrease were explained. The implication of these results revealed that hardening of steels with locally pulverized cassava leaves is cost effective and environmentally safer than conventional means.